(a) Field of the Invention
The unidirectional light emitting diode drive circuit in bi-directional divided power impedance is disclosed by that an AC power or a periodically alternated polarity power is used as the power source to supply to the resistive impedance components, or inductive impedance components, or capacitive impedance components in mutual series connection, whereby the power source voltage is divided. Thereof, it is characterized in that the said divided power is further rectified by a rectifier device to supply unidirectional DC power output to drive an uni-directional conducting light emitting diode, or to drive at least two rectifier devices which are respectively parallel connected across the two ends of the first impedance and the second impedance while the AC powers of the first impedance and second impedance are respectively converted to DC power output through the said rectifier devices, thereby to drive the unidirectional conducting light emitting diodes individually.
(b) Description of the Prior Art
The conventional light emitting diode drive circuit using AC or DC power source is usually series connected with current limit resistors as the impedance to limit the current to the light emitting diode, whereof the voltage drop of the series connected resistive impedance always result in waste of power and accumulation of heat which are the imperfections.